/*
 * This file is open source software, licensed to you under the terms
 * of the Apache License, Version 2.0 (the "License").  See the NOTICE file
 * distributed with this work for additional information regarding copyright
 * ownership.  You may not use this file except in compliance with the License.
 *
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
/*
 * Copyright (C) 2021-present ScyllaDB
 */

#pragma once

#include <seastar/core/coroutine.hh>

namespace seastar::coroutine {

/// Wrapper for propagating an exception directly rather than
/// throwing it.
///
/// \note It will not work on coroutines which return future<>, due to the fact
/// that it's not legal to specify both return_value and return_void.
/// The mechanism works fine for future<T> though.
///
/// Example usage:
///
/// ```
/// co_return coroutine::exception(std::make_exception_ptr(std::runtime_error("something failed miserably")));
/// ```
struct exception {
    std::exception_ptr eptr;
    explicit exception(std::exception_ptr eptr) : eptr(std::move(eptr)) {}
};

/// Helper for creating a coroutine::exception instance
///
/// Example usage:
///
/// ```
/// co_return coroutine::make_exception(std::runtime_error("something failed miserably"));
/// ```
template<typename T>
exception make_exception(T&& t) {
    return exception(std::make_exception_ptr(std::forward<T>(t)));
}

}